Window assemblies with sliding window sash include opposingly positioned window jamb liners that guide vertical movement of the sliding window sash. The jamb liners are often extruded since this is a cost-effective way of manufacturing an elongated, continuous shape. Typically, the window jamb liner includes one or more channels extending the length of the jamb liner that act as guides for the sash, and the sliding window sash include one or more friction-generating sash supports operably movably positioned in the jamb liner channels for controlling the movement of the sliding window sash. A sash-engaging member extends from each friction-generating sash support through a slot in the jamb liner into engagement with the window sash.
A variety of window jamb liners are known which have slots extending the full length of the window jamb liner. However, dirt, debris and foreign objects may collect in the slots, particularly at an end of the window jamb liner where the slots are not wiped clean by movement of the sliding window and the sash-engaging member. Further, long open slots create an unattractive appearance since they are in a highly visible location.
One alternative to resolve this prpblem is to cover the window jamb liner slot, and various ways have been contrived for attempting to do so with respect to all or portions of this slot. Some jamb liners use a striplike insert positioned in the slot to cover portions of it. In another type of jamb liner, the slot comprises a narrow slit in a deformable portion of a dual-durometer co-extruded jamb liner. However, these methods require secondary operations which are expensive and labor-intensive and/or utilize separate parts, complex extrusions, etc., which may present quality control problems. Further, the slot-covering insert or flap may come loose or deform over time, thus resulting in the same problem they were intended to solve.
Thus, an apparatus and process for efficiently and cost-effectively forming elongated holes or discontinuous slots or grooves of predetermined length and position in window jamb liners, and particularly in extruded jamb liners, has long been needed. Further, apparatus, processes and articles are desired which solve the aforementioned problems.
However, forming discontinuous slots, holes or grooves in an extrusion requires the use of special measures and equipment, or secondary operations which are labor intensive and may present quality control problems. It is desirable to form the discontinuous slots, holes or grooves without the need for complex machinery, since complex machinery requires continuing maintenance. Also, it is desirable to form these features without using rotary or other cutting bits or blades, which require frequent sharpening of the cutting surfaces, are likely to leave rough or sharp edges, and impose additional expense.